One such nozzle is described, inter alia, in French patent number 2 547 737 and is constituted by associating a channel which is delimited at a spray or front end by a wall which is pierced by a central orifice, and a rod whose outside section is slightly less than the inside section of the channel, the rod being placed inside the channel, thereby leaving an empty section of small volume and thus avoiding a dead volume that would be prejudicial to good spraying. This disposition eliminates the risk of expulsion towards the front of the nozzle, which risk is not negligible when pressure is high, and it facilitates molding the pushbutton, enabling a channel of great length to be molded in a single piece.
A pushbutton is designed to be mounted on the piston rod of the pump, commonly called the "valve" rod, which is constituted by a hollow tube controlling the piston, with the substance to be sprayed being delivered via said tube. In the present invention, the spray jet is substantially perpendicular to the axis of the valve rod.